Graduate Fellow

Tracing the Origins of an Endemic Flora, and Extending a Study of Divergence Dating Disparity

PI(s): Barbara H. Dobrin (University of Arizona (Tucson,AZ))
Start Date: 11-Aug-2014
End Date: 30-Nov-2014
Keywords: systematics, paleontology, biogeography, computational modeling, speciation

New methods in phylogenetic biogeography can model a range of complex biogeographic processes, incorporate temporal and ecological data, and apply a variety of approaches to inference. Advances in these methods open new possibilities for tracing the origins of locally endemic biotas and those with rare adaptations, groups that have long interested biogeographers. Among these are flora endemic to serpentine soils, harsh, low-nutrient habitats that are arranged disjunctly in landscapes and contrast starkly with surrounding habitats in their environmental properties. Using emerging biogeographic methods, I will test hypotheses about the interactions between range shifts and diversification events in the assemblage of serpentine plants in California. To develop a phylogenetic resource for this study, I will construct a time-calibrated phylogenetic tree encompassing all California seed plants for which phylogenetically informative molecular sequences are available (approximately 5,000 species). The new fossil-based calibration data accumulated for this study will help extend the analyses of molecular and fossil dating disparities underway in the NESCent lab of Postdoctoral Fellow Dr. Daniel Ksepka. Calibrations gathered for this project will also expand the holdings of the Fossil Calibration Database, a product of NESCent’s Fossil Calibration Database Working Group.